This invention relates to an apparatus and method for sequentially removing articles from a stack of nested articles and for controlling their movement to a location remote from the stack.
The method and apparatus of the present invention is particularly suited for denesting and feeding large multiple cell cartons, such as eighteen cell egg cartons, to a conveyor for subsequent printing operation. Examples of eighteen cell egg cartons are disclosed in the U.S. Pat. Nos. 4,625,905, and 4,625,906 of Raj K. Mangla. Cartons of this type may be made of wood pulp or, more recently, formed from sheets of plastic material by a thermoforming process. After the cartons have been formed, it is the practice to print the top surface of the cover with a suitable wording and/or design. Eighteen cell egg cartons are substantially larger than twelve cell egg cartons and thus are more difficult to handle on an automatic assembly line. After the cartons have been thermoformed they are nested one within the other into high vertical stacks where they are stored for subsequent operations. In order to perform the subsequent operations it is necessary to denest the cartons from the stacks. This operation has been performed in the past by the use of a pair of feed screws through which the cartons are sequentially fed. The feed screws had the same thread and rotated in the same direction. Such feed screws have been satisfactory for denesting twelve cell egg cartons, however, they have left considerable to be desired with regard to denesting eighteen cell egg cartons.
It is an object of the present invention to provide a method and apparatus for sequentially removing articles from a stack of nested articles and for controlling their movement to a location remote from the stack and doing so in a manner suitable for automation.